The Ass In the Lion's Skin

An Ass found a Lion's Skin, and dressed himself up in it. Then
he went about frightening every one he met, for they all took him
to be a lion, men and beasts alike, and took to their heels when
they saw him coming. Elated by the success of his trick, he loudly
brayed in triumph. The Fox heard him, and recognised him at once
for the Ass he was, and said to him, "Oho, my friend, it's you, is
it? I, too, should have been afraid if I hadn't heard your
voice."